Personnel safety guard for machinery

ABSTRACT

A safety guard to prevent injury to personnel in connection with the operation of machinery. The guard comprises a plurality of horizontally disposed elongated panels supported in a closed position with the panels in substantially edge to edge relationship and combining to cover the hazardous area. Means is provided for moving the panels vertically in unison to an open position wherein the panels are in side by side stacked relationship to provide a clear area for access to the machine. The guard is arranged to be readily operated without effort by the operator and to provide optimum safety.

United States Patent Mikulin 151 3,654,821 [451 Apr. 11, 1972 [54]PERSONNEL SAFETY GUARD FOR- MACHINERY [72] Inventor: Tom T. Mikulin,1469 Bellevue Avenue,

Burlingame, Calif. 94010 [22] Filed: May 11, 1970 [21] Appl. No.: 36,266

52 U.S.Cl ..74/6l2,83/544, 100/53 51 1111.01 ..F16p3/00 [58]FieldofSearch ..74/608,616,615,614,613,

[56] References Cited UNIT ED STATES PATENTS 2,724,287 11/1955 Knoth..74/6l6 FOREIGN PATENTSOR APPLICATIONS Great Britain PrimaryExaminer--William F. ODea Assistant Examiner-F. D. ShoemakerAttorney-Gordon Wood [57] ABSTRACT A safety guard to prevent injury topersonnel in connection with the operation of machinery. The guardcomprises a plurality of horizontally disposed elongated panelssupported in a closed position with the panels in substantially edge toedge relationship and combining to cover the hazardous area. Means isprovided for moving the panels vertically in unison to an open positionwherein the panels are in side by side stacked relationship to provide aclear area for access to the machine. The guard is arranged to bereadily operated without effort by the operator and to provide optimumsafety.

4 Claims, 6 Drawing Figures PATENTEDAPR 11 I972 SHEET 1 OF 2 lii,

55 INVENTOR.

TOM T. MIKULI N 52 9 v i 6 11% W PATENTEDAPR 1 1 m2 SHEET 2 BF 2INVENTOR,

TOM T. M IKUL I M PERSONNEL SAFETY GUARD FOR MACHINERY This inventionrelates to safety guards of the type employed to prevent injury topersonnel from the operation of machinery. Heretofore the design ofsafety guards for machines has generally been considered a separateproblem in each instance depending on the size, orientation, and themethod of actuation of the machine. In most cases it is essential thatthe guard act as a barrier when the machine is in operation and at thesame time be readily removed from the working area to permit access tothe machine for purposes of adjustment, changeover, and correction ofmalfunctioning.

In many instances prior art safety guards have required a considerableamount of room especially when it is desired to open the guard to obtainaccess to the machine. In other instances the movement of the guard fromopen position to closed position and vice versa has required aconsiderable amount of work on the part of the operator thus causingdelays and impairing the efficiency of the guarded machine.

The main object of the present invention is to generally improve safetyguards for machinery and to overcome many of the disadvantages of priorart devices of like nature.

Another object of the invention is the provision of a safety guard formachinery which is readily opened and closed by the operator withoutgreat effort and with much more speed than has heretofore been possible.

Still another object of the invention is the provision of a safety guardwhich is designed to provide optimum effectiveness as a barrier and atthe same time be easily opened and closed.

Other objects and advantages will be apparent from the followingspecification and from the drawings:

FIG. 1 is a front elevation of the guard with most of the panelactuating mechanism omitted because of the smallness of the scale.

FIG. 2 is a greatly enlarged fragmentary side elevation of the righthand side of the guard with portions broken away to show internalstructure.

FIG. 3 is a vertical sectional view taken in a plane indicated by lines3-3 in FIG. 2.

' FIG. 4 is a fragmentary end elevation showing the locking mechanism.

FIG. 5 is an enlarged horizontal sectional view taken in a planeindicated by lines 55 in FIG. 1.

FIG. 6 is a fragmentary horizontal sectional view through the lower endof the guard showing the locking mechanism.

In detail, and first with reference to FIG. 1., the guard is shown inits entirety but omitting mounting means including brackets that may beemployed to secure it in a position covering the hazardous area. It willbe understood in this connection that the guard may vary greatly in sizedepending upon the area to be protected. Furthermore depending on theparticular machine involved the method of securing the guard in front ofthe machine will vary depending on the adjacent structure to which theguard is to be secured. In connection with the following disclosure itwill therefore be understood that the frame of the guard must be mountedas desired in a fixed position depending on the particular environmentinvolved.

The guard is provided with a peripherally extending frame including apair of horizontally spaced end members 1, 2, and a top frame member 3.Said frame members are secured together by any convenient means toconstitute the fixed support for the guard.

Extending horizontally between the side frame members 1, 2 are aplurality of panels 5. Each panel 5 may be divided into two parts asindicated in FIG. 1 in the event the length of the guard is fairly long.In many instances the guarded area is sufficiently narrow so that eachpanel may be made in one piece. Each panel is provided at its oppositeends with end pieces 6 which may be made from angle bar so that thepanel material may be secured to one leg of the angle bar while theother leg provides means for pivotally supporting the panel.

In the particular guard shown in FIG. 1 upper panels 5A, 5B, 5C andlower panels 5F, 5G are provided with expanded metal 7 whereas theintermediate panels SD, SE are provided with transparent material suchas a tough transparent plastic indicated at 8. By this arrangement anadequate barrier is pro vided when the panels are in closed positionshown in FIG. 1 and at the same time the operator may view the operationof the machine indicated by dot dash lines at 10 in FIG. 1 through thetransparent panels SD, SE.

The panels 5 are adapted to be moved from the closed position shown inFIG. 1 to an open position shown in dot dash lines in FIG. 3 in whichthe panels 5 are in substantially stacked relationship under the top 3of the frame. In such open position it will be apparent that a generousaccess area is available through the frame permitting the operator toperform whatever functions are required on the machine.

The guard is moved from closed to open position by the operator by meansof a horizontally extending hand bar 12 adjacent the lower frame member4 of the guard. As will be explained in greater detail later on thepanels 5 move in unison under the control of lazy tong mechanismsactuated by movement of the bar 12. In order to minimize the effortrequired by the operator in opening the guard counterweights 9 areprovided which move from the upper position shown in FIG. 1 to a lowerposition as the panels 5 are raised to their upper position shown in dotdash line in FIG. 3. Smooth actuation of the guard is achieved by aparallel motion device which will now be described.

Rotatably supported at the lower ends of sides 1, 2 are pulleys 13, 14around which is reeved a flexible wire. The inner runs 15, 16 of thewire extend from the pulleys 13, 14 up to connectors 17, 18 which inturn are pivotally connected to lower panel 5G in a manner to bedescribed. The left hand inner run 15 continues up from the connector 17to a small pulley 19 and then horizontally within the frame top 3 to anouter pulley 20 at the upper end of side frame member 2 and thence downto the right hand counterweight 9. From said counterweight the outer run22 of the wire extends downwardly around pulley 14. In like manner theinner run 16 at the right hand end of the frame is reeved over a pulley24, then along the top 3 and around a pulley 23 at the upper end of sideframe member 1 thence down to the pulley 13.

From the above general description it will be seen that the wire insuresparallel motion of the panels when the same are moved and at the sametime the counterweights 9 may be adjusted in weight so thatsubstantially no effort is required to move the guard from closed toopen position and vice versa.

It will be understood that the invention also contemplates horizontalmovement of the guard to a position alongside one of the end members 1,2 of the frame.

Referring now to the details of the guard actuating means shown in FIGS.2, 3, and 5 the upper panel 5A is pivotally connected by a pivot 27 tothe lower end of a short link 25 which is swingably secured at its upperend to a rod 26 extending horizontally the length of the guard andsecured at its opposite ends to end frame members 1, 2. Centrallybetween its opposite side edges panel 5A is provided at each end with apivot pin 30 which is passed through a hole in the laterally outwardlyfacing flange of angle bar 6. Each pivot pin 30 is formed with anintegral annular collar 31 (FIG. 5) which serves to space apart an outerlink 32 carried at its opposite ends by panel 5A and an inner link 33pivoted on pin 31 and pivotally connected at its upper end to the lowerends of a pair of links 23 (FIG. 3). It will be seen from FIGS. 2, 3that the pair of links 23 are swingable at their upper ends on rod 26together with link 25.

Each panel 5 is pivoted in like manner as panel 5A with the same linkagearrangement as above described except for the omission of short links23, 25. Said lazy tong linkage arrangement permits the panels to bemoved to their open position at the upper side 3 of the frame asindicated in dot dash lines in FIG. 3.

Referring to FIG. 5 the pin 30 is fixedly secured to the panel 56 bymeans of nut 34 and rotatably supported on each pin 30 is a roller 38which is received within a slot 39 formed between the opposed flanges ofa substantially channel shaped element 40. Said element 40 is fixedlysecured to a similar channel shaped element 41 and together saidelements constitute the side frame member 2. Left hand frame member 1 issimilarly constructed.

The particular pin 30 carried by panel A is preformed with an extension43 (FIG. 5) to which is secured the wire connector 18. From thisstructure it will be seen that the pins 30 move smoothly along thelength of slot 39 under the control of rollers 38 when the panels 5 aremoved.

As best seen in FIG. 5 counterweights 9 are secured by bolts 45 toslides 46 which include a portion 47 slidable within the slot 39 ofchannel 41.

Although the weight of counterweights 9 may be predetermined so thatthere is no tendency for the guard to open from its closed positionshown in FIG. 1 it is nevertheless preferable to have saidcounterweights of such a weight that substantially no effort is requiredto actuate the guard.

Since vibration of the guarded machine may tend to open the guard fromthe closed position of FIG. 1 it is preferable to provide a positivelocking means for retaining the guard in closed position. Such positivelocking means is shown in FIGS. 2, 4, 6.

The hand bar 12 is fixedly secured at its opposite ends to the anglebars 6 of bottom panel 50 by means of brackets 50 which are shaped so asto position the hand bar at a point spaced outwardly from the verticalplane of the guard where said bar is readily grasped by the operator.Rotatably supported at its opposite ends in brackets 50 is a rod 51 tothe opposite ends of which are secured bosses 52 by means of pins 53(FIG. 6). Carried by the bosses 52 are small rollers 55 which areadapted to be received within notches 56 (FIG. 4) formed in plates 57which in turn are integrally secured to the lower ends of sides 1, 2.

Integral with rod 51 and with each boss 52 is a plate 59 provided with ahandle 60 by which the plate 59, boss 52 and rod 51 may be swung from anupper position indicated in dot dash lines in FIG. 4 to the lower fullline position.

Plate 59 is provided with an extension 62 (FIG. 4) which is adapted tobe received under a pin 64 carried by bracket 50 when the hand bar 12 isin its lowermost position. By employing the pin 64 as a pivot theoperator may swing either plate 59 downwardly from the dot dash positionof FIG. 4 so that the roller 55 is engaged within the notch 56. Suchmovement of plate 59 is performed with the hand bar 12 held downwardlyin its lowermost position and against the resiliency of'the lazy tongmechanism above described. When roller 55 is thus received in notch 56the mechanism is positively locked and there is no danger of vibrationcausing the panels 5 to creep upwardly to open position. When it isdesired to open the guard a positive movement of bar 12 downwardlytogether with positive upward swinging of plate 59 is required torelease the device from locked position. Since there is a plate 59 ateach end of rod 51 either one may be operated.

In the event the panels 5 are required to be of such a length thatsupport is required intermediate their length as indicated in FIG. 1 alazy tong mechanism may be employed between the panel portions similarto that shown in FIGS. 2, 3.

The operation of the counterweights 9 may be made smooth and unnecessarynoise eliminated by providing nylon pads 66 at the upper and lower endsof said counterweights. These pads are similar in shape to the rollers38 and are adapted to slide within the adjacent slot 39 of the frameside.

I claim:

1. A safety guard adapted to be positioned adjacent a machine such as apunch press to protect personnel from injury comprising:

a vertically disposed frame defining a vertical working area centrallythereof,

a plurality of horizontally elongated panels of protective material,

means supporting said panels for movement in unison from a closedposition with said panels approximately within said working area andcombining to cover such area to an open position atone end of said framewith said panels in substantially side by side stacked relationship toprovide access through said central area to such machine,

said panels being supported at their opposite ends by lazy tongmechanisms to permit such movement,

said frame being formed in its opposite vertically extending marginalportions with longitudinally extending slots for receiving therein thecentral pivots of said lazy tong mechanism.

2. A guard according to claim 1 wherein locking means is provided forpositively holding said panels in closed position.

3. A guard according to claim 1 wherein movement of said panels iscontrolled by a parallel motion mechanism to insure pure translation ofsaid panels.

4. A guard according to claim I wherein a counterweight is employed tofacilitate movement of said panels upwardly to open position.

1. A safety guard adapted to be positioned adjacent a machine such as apunch press to protect personnel from injury comprising: a verticallydisposed frame defining a vertical working area centrally thereof, aplurality of horizontally elongated panels of protective material, meanssupporting said panels for movement in unison from a closed positionwith said panels approximately within said working area and combining tocover such area to an open position at one end of said frame with saidpanels in substantially side by side stacked relationship to provideaccess through said central area to such machine, said panels beingsupported at their opposite ends by lazy tong mechanisms to permit suchmovement, said frame being formed in its opposite vertically extendingmarginal portions with longitudinally extending slots for receivingtherein the central pivots of said lazy tong mechanism.
 2. A guardaccording to claim 1 wherein locking means is provided for positivelyholding said panels in closed position.
 3. A guard according to claim 1wherein movement of said panels is controlled by a parallel motionmechanism to insure pure translation of said panels.
 4. A guardaccording to claim 1 wherein a counterweight is employed to facilitatemovement of said panels upwardly to open position.